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Endoplasmic reticulum-mediated phagocytosis is a mechanism of entry into macrophages

Etienne Gagnon1, Sophie Duclos, Christiane Rondeau

  • 1Département de Pathologie et Biologie Cellulaire, Université de Montréal, Montréal, Québec, Canada.

Cell
|August 2, 2002
PubMed

Insights

The endoplasmic reticulum (ER) provides membrane for phagosome formation in macrophages, a process vital for fighting infections. This ER-mediated phagocytosis is exploited by pathogens to evade destruction.

Area of Science:

  • Cell Biology
  • Immunology
  • Infectious Diseases

Background:

  • Phagocytosis is a critical innate immune mechanism for pathogen clearance.
  • The source of membrane for phagosome formation in macrophages has been a subject of investigation.

Purpose of the Study:

  • To investigate the role of the endoplasmic reticulum (ER) in phagosome formation.
  • To understand the mechanisms and implications of ER involvement in phagocytosis.

Main Methods:

  • Studied membrane dynamics during phagocytosis in macrophages.
  • Investigated the involvement of phosphatidylinositol 3-kinase in ER-mediated phagocytosis.

Main Results:

  • Identified fusion of the ER with the macrophage plasma membrane as a primary source of phagosome membrane.
  • Observed successive ER association with maturing phagosomes during phagolysosome biogenesis.
  • Found ER-mediated phagocytosis is regulated by phosphatidylinositol 3-kinase and utilized for various cargo, unlike in neutrophils.

Conclusions:

  • The endoplasmic reticulum exhibits versatile fusion capabilities, contributing significantly to phagocytosis in macrophages.
  • Intracellular pathogens may exploit ER-mediated phagocytosis for survival and evasion of host defenses.
  • ER involvement in phagocytosis appears to be cell-type specific, differing between macrophages and neutrophils.

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